In the field of normal temperature air separation plant manufacturing, especially in products such as PSA nitrogen generators, PSA oxygen generators and VPSA oxygen generator, Gamma Gas holds the lead in gposition.

Industrial Oxygen Generator

Hospital Oxygen Generator

PSA oxygen generator uses similar process and principle of PSA nitrogen generator. The differences are: Different adsorbent:Carbon molecular sieve is used for nitrogen generator, zeolite molecular sieve is used for oxygen generator;Different adsorption time:Oxygen generator has longer adsorption time, while nitrogen generator has more complicated desorption process.

Hospital oxygen generator is developed from industrial oxygen generator, it has same working principle. As the oxygen produced is used directly by human body, the oxygen must be clean and safe. Also the operation of this equipment must be reliable. When there is problem with it, spare oxygen must be available. There are several differences between industrial and hospital oxygen generators.

AdsorptionThere are two adsorbers with carbon molecular sieve. When cleaning compressed air enters the gas inlet of adsorber A, it flows to outlet, passing through carbon molecular sieve, O2、CO2 and H2O are adsorbed, produced nitrogen goes out of adsorber outlet.

DesorptionAfter some time, the carbon molecular sieve in adsorber A is adsorb-saturated. Compressed air is switched to adsorber B to adsorb O2 and produce N2, at the same time, carbon molecular sieve in adsorber A desorbs and regenerates itself. The desorption of molecular sieve is realized by vent valve. When empty air in adsorbers, the pressure inside quickly drops down to normal pressure and the adsorbed O2、CO2、H2O are desorbed.

BlowingTo thoroughly regenerate carbon molecular sieve, product nitrogen from adsorber outlet or nitrogen buffer tank is used to blow out the remaining O2、CO2、H2O of adsorbers.

Pressure equalizationBefore the switch between two adsorbers, there is a process of pressure equalization, it is used to promptly increase adsorption pressure and nitrogen rate of recovery. Pressure equalization means connecting two adsorbers, let gas in one adsorber(to be desorbed) enter the other one(to be adsorb), then the two adsorbers can have equal pressure.This system adapts unequal pressure equalization process, the nitrogen rate of recovery is further improved, which reduces the energy consumption of the whole system.

Vacuum swing adsorption (VSA) is a non-cryogenic gas separation technology.Using special solids, or absorbents, VSA segregates certain gases from a gaseous mixture under minimal pressure according to the species' molecular characteristics and affinity for the absorbents. These absorbents (e.g., zeolite ) form a molecular sieve and preferentially absorb the target gas species at near ambient pressure. The process then swings to a vacuum to regenerate the absorbent material.

Core Technology in GAMMA

PSA nitrogen/oxygen generation principle

Pressure Swing Adsorption (PSA) is a technology used to separate some gas species from a mixture of gases under pressure according to the species' molecular characteristics and affinity for an adsorbent material. It operates at near-ambient temperatures and so differs from cryogenic distillation techniques of gas separation. Special adsorptive materials (e.g., zeolites) are used as a molecular sieve, preferentially adsorbing the target gas species at high pressure. The process then swings to low pressure to desorb the adsorbent material.

Pressure swing adsorption processes rely on the fact that under pressure, gases tend to be attracted to solid surfaces, or "adsorbed". The higher the pressure, the more gas is adsorbed; when the pressure is reduced, the gas is released, or desorbed. PSA processes can be used to separate gases in a mixture because different gases tend to be attracted to different solid surfaces more or less strongly. If a gas mixture such as air, for example, is passed under pressure through a vessel containing an adsorbent bed that attracts nitrogen more strongly than it does oxygen, part or all of the nitrogen will stay in the bed, and the gas coming out of the vessel will be enriched in oxygen. When the bed reaches the end of its capacity to adsorb nitrogen, it can be regenerated by reducing the pressure, thereby releasing the adsorbed nitrogen. It is then ready for another cycle of producing oxygen enriched air.

This is exactly the process used in portable oxygen concentrators used by emphysema patients and others who require oxygen enriched air to breathe.

Using two adsorbent vessels allows near-continuous production of the target gas. It also permits so-called pressure equalisation, where the gas leaving the vessel being depressured is used to partially pressurise the second vessel. This results in significant energy savings, and is common industrial practice.

Vacuum swing adsorption (VSA) technology.

Using special solids, or absorbents§, VSA segregates certain gases from a gaseous mixture under minimal pressure according to the species' molecular characteristics and affinity for the absorbents. These absorbents (e.g., zeolites§) form a molecular sieve§ and preferentially absorb the target gas species at near ambient pressure. The process then swings to a vacuum to regenerate the absorbent material.

VSA differs from cryogenic distillation techniques of gas separation§ as well as pressure swing adsorption§ (PSA) techniques due to the fact that it operates at near-ambient temperatures and pressures. VSA may actually be best described as a subset of the larger category of PSA. It differs primarily from PSA in that PSA typically vents to atmospheric pressures, and uses a pressurized gas feed into the separation process. VSA typically draws the gas through the separation process with a vacuum. For oxygen and nitrogen VSA systems, the vacuum is typically generated by a blower. Hybrid VPSA§ systems also exist. VPSA systems apply pressurized gas to the separation process and also apply a vacuum to the purge gas. VPSA systems, like one of the portable oxygen concentrators, are among the most efficient systems, measured on customary industry indices, such as recovery (product gas out/product gas in), productivity (product gas out/mass of sieve material). Generally, higher recovery leads to a smaller compressor, blower, or other compressed gas or vacuum source and lower power consumptions. Higher productivity leads to smaller sieve beds. The consumer will most likely consider indices which have a more directly measurable difference in the overall system, like the amount of product gas divided by the system weight and size, the system initial and maintenance costs, the system power consumption or other operational costs, and reliability.